Paul wolf



P. WOLF MINER'S LAMP May 26, 1931.

Filed April 28, 19150 By'. W [74615.

Patented May 26, 1931 PATENT OFFICE PAUL WOLF, F ZWICKAU, GERMANYMINER/S LAMP Application filed April 28, 1930. Serial No. 448,061.

My invention relates to electric lamps for accumulator working, and moreparticularly to a head lamp for miners, which consists of the lampitself to be carried on the miners head gear and an accumulator, to becarried on the back or on a belt, the accumulator being connected withthe lamp itself by a cable.

The object of my invention is in general to make such lamps particularlysuitable for use in mines, and the invention is particularly directedtowards providing a simple construction, that will give the minimumpossible occasion for disturbances, and also to protect the lamp againstunauthorized opening, and other unauthorized treatment by the miner, asa result of which explosions of fire damp might be brought about, whileenabling the accumulator to be conveniently charged without separatingit from the lamp.

The invention further provides for switching off the lamp or lamps inthe event of their being endangered by a shock.

In pursuance of these objects the lamp casing contains firstly a rotaryswitch, consisting of a non-conducting spindle rotatable from outside,with conducting projections in co-operation with stationary contactsprings fitted into the lamp casing, the said contact springs beingconductively connected in pairs by the said conducting projectionsaccording to the angularposition of the spindle, for the purpose ofeffecting the various switching operations requisite for operating thelamp.

In the simplest case only one lamp bulb is provided, which has to beswitched on and off. There may however be provided a two-filament lamp,or else two lamp bulbs may be 0 provided. In these cases the projectionson the switch spindle and the connections associated with the contactsprings are so arranged that the filaments or lamp bulbs can be switchedon individually or collectively, or else one filament or the other, orone lamp or the other of different candle power, may be switched onalternatively. All this admits of being easily obtained with the rotaryswitch with its conducting projections and suitably arranged contactsprings.

In order furthermore to make the lamp permanently currentless in theevent of damage, or even in the case of a shock seriously endangeringthe lamp though not already harming it, and thus reliably preventing theignition of fire damp, a very simple and reliably acting means isemployed. It consists in locating the lamp holder or holders upon apivotally arranged plate, which is held by a spring in the normalposition, which is determined by a stop. The plate is connected with onepole of the current supply, whereby the conductive connection with theside contact of the lamp base cap, that is, with the screw-thread of theEdison screw lamp holder or the transverse pins of the Swan lamp base,is established. The other pole of the current supply is conductivelyconnected by a contact spring with the end pole of the lamp base cap.This contact spring may at the same time be the spring that presses theplate against the stop and thereby holds it in its normal position. Thissecond pole of the current supply is connected at the other end with acontact spring which is touched by a contact finger on the plate whenthe latter is deflected out of its normal position against the pressureof the spring. A short circuit is thereby established between the twopoles of the current supply, which makes the lamp permanentlycurrentless by virtue of a fuse interposed in the path of the currentand fitted into the lamp casing or even into the accumulator, the saidfuse blowing upon the occurrence of a short circuit.

In order to be able to charge the accumulator through the lamp, and thussave opening the accumulator casing every time, I have furthermoreprovided in the lamp casing two plug sockets, which are each connectedwith one pole of the current supply to the lamp. The accumulator canthus be charged if the plugs of a plug contact of known arrangement areintroduced into these sockets, the said plug contact closing thecharging circuit. N ow it would be hazardous if current could be takenfrom the accumulator by introducing metallic members into the plugsockets in mines rendered dangerous by fire damp. I therefore provide aclosure member which covers the apertures of the plug sockets, and whichin its turn can be secured by lead sealing or even by the magnetic lockwhich is known in connection with miners lamps.

On the same ground also, the opening of the lamp casing by the miner isto be prevented. For this purpose I provide a member which prevents theloosening of the screw ring for the cover glass of the lamp casing, andwhich in its turn can be secured by lead sealing or by a magnetic lock.

It is particularly advantageous if the two locking members or securingmeans just dealt with are united into one. It is then only necessary toprovide one lead seal or one magnetic look. This combination may forexample be effected by arranging a flap rocking about a fixed point onthe casing and covering on'the one hand the apertures of the plugsleeves, and on the other hand engaging with a finger over the saidscrew ring.

The invention is illustrated by way of eX- ample in the accompanyingdrawings, in which Figure 1 is a side sectional elevation of a lampaccording to the invention,

Figure 2 is a front view, with the frame ring, the disc, the radiationscreen and the lamps removed,

Figure 3 a front view with the lamp holders and the plate in which theyare mounted removed, and

Figure 4 a back View.

The lamp casing 1 consists of a hemispherical hollow body of insulatingmaterial and a screw-threaded tubular coupling member 1a on its rearside. In this body is supported the switch spindle 9, of insulatingmaterial, on which conducting projections 28 are provided. By thecoupling member 1a the cable 4, with the conductors 12 aml 13, isintroduced into the lamp.

The conductor 12 leads to a screw 14, by which the spring 23 is heldfast. The screws 14a hold springs 11 and 11a, which may also be in onepiece. The springs 11a press against the central poles of the lamps 8.

The conductor 13 leads to a screw 15, which, together with a screw 17,holds the bearing piece 20 firmly to the lamp casing. To the piece 20 issecured a pin 19, round which a plate 21 can swing. It is howeverpressed by the springs 11a against a stop piece 18 secured by the screw17, and in this way held fast in a particular position under normalcircumstances. Upon the plate 21 are mounted the holder rings 22 for thelamps 8. Two fingerlike projections on the plate 21 are located undernormal circumstances a short distance above the springs 11.

On the under side of the lamp casing are located plug sockets 25 and 26.The socket 25 is conductively connected with the conductor 13 by aprojection into which a screw 15 is screwed. The electrical connectionof the socket 26 with the conductor 12 is established by a screw 27,through a member 23a and the screw 14. Vith the screws 29 is rotatablyconnected a closure cover 30, which covers the sockets 25 and 26 and atthe same time engages with a finger 30a over the frame ring 2.

If the accumulator associated with the lamp is to be charged withouthaving to interrupt the cable connection between it and the lamp or openthe accumulator, the lead seal is released at 31, and the closure cover30 rotated about the screw 29, so that the plug sockets 25, 26 becomeaccessible. Since the latter, as described above, are in conductivecommunication with the conductors 12 and 13, and therefore with thepoles of the accumulator, the accumulator can be charged through thelamp from a source of current by introducing a plug member into thesockets 25, 26. On the front aperture of the lamp casing is mounted thereflector 7 and the glass plate 3, which are held fast by the frame ring2.

If it is desired to switch on the right-hand or the left-hand lamp it isonly necessary so to rotate the switch spindle 9 that the conductingprojection 28 conductively connects the spring 23 with one of thesprings 11. The circuit is then as follows From the accun'lulator to theconductor 12 by way of the spring 23, the contact piece 28 to thesprings 11 and 11a and to the terminal pole of the lamp; from the lampholder 22 by way of the plate 21, the piece 20 to the conductor 13 andthe back to the accumulator. The spring 11 is therefore connected, whenone of the two lamps is switched on, with one pole (conductor 12), byway of the contact piece 28 and the spring 23. The other pole (conductor13) bears directly on the plate 21, and accordingly also on thefinger-like projection 10. If there acts upon the lamps 8 a considerableshock, such as would endanger them, as being capable for instance ofbreaking the protecting glass or the bulb, or has in fact broken them,the springs 11a yield. The plate 21 swings about the pin 19 and thefinger-like projections 10 of the plate 21 touch the springs 11, that isto say, a short circuit occurs, which melts a fuse fitted at some otherposition, for instance on the accumulator. The circuit is thereforepermanently interrupted, and the danger of igniting the firedamp whenthe lamp is smashed is thereby eliminated. In order however to preventthe miner from screwing off the lamp there is fitted a finger 30a, whichaccording to the drawing is structurally connected with the closurepiece 30 for the plug sockets but might alternatively be separatelyfitted, and would then of course be protected by securing means of itsown, such as a lead seal for example. The lug 31 of the closure member30, in conjunction with the extension 32 fitted to the lamp casing,enables the locking or closing member to be secured by means of a leadseal.

The hook 5 secured by means of a screw 5a to the lamp casing, isintended for hanging the lamp on the miners cap.

What I claim is 1. An electric lamp adapted to be energized by anaccumulator and to be used as a miners head lamp or for like purposes,comprising a lamp casing, an electric lamp bulb mounted in the casing,current supply conductors entering the lamp casing and adapted to beconnected externally to an accumulator, a switch spindle journaled inthe casing, means such as a handle for rotating the switch spindle fromoutside the casing, and means provided on the switch spindle forestablishing and interrupting an electric circuit through the lamp bulband the current supply conductors.

2. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, a plurality of electric lamp bulbs mounted in the casing,current supply conductors entering the lamp casing and adapted to beconnected outside the lamp casing to an accumulator, a switch journaledin the casing, means such as a handle for rotating the switch spindlefrom outside the casing, and means provided on the switch spindle forestablishing and interrupting electric circuits through the several lampbulbs and the current supply conductors.

3. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, a plurality of electric lamp filaments mounted in the casing,current supply conductors entering the lamp casing and adapted to beconnected outside the lamp casing to an accumulator, a switch spindlejournaled in the casing, means such as a handle for rotating the switchspindle from outside the casing, and means provided on the switchspindle for establishing and interrupting electric circuits through theseveral lamp filaments, and the current supply conductors.

4. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, a plurality of electric lamp filaments mounted in the casing,current supply conductors entering the lamp casing and adapted to beconnected outside the lamp casing to an accumulator, a non-conductingswitch spindle journaled in the casing, means such as a handle forrotating the switch spindle from outside the casing, contact springsmounted in the casing, and conducting projections on the switch spindleadapted to place the contact springs in electric connection with oneanother in pairs in certain positions of the switch spindle, therebyestablishing electric circuits through the lamp filaments and thecurrent supply conductors.

5. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, a lamp holder plate movably mounted in the casing, a stopagainst which the lamp holder plate normally bears, a spring tending tohold the lamp holder plate against the stop, lamp holders mounted on thelamp holder plate, a plurality of electric lamp bulbs mounted in thelamp holders, current supply conductors entering the lamp casing andadapted to be connected outside the lamp casing to an accumulator, aswitch spindle journaled in the casing, means such as a handle forrotating the switch spindle from outside the casing, means provided onthe switch spindle for establishing and interrupting electric circuitsthrough the several lamp bulbs and the current supply conductors, acontact piece adapted to be touched by the yieldingly mounted lampholder plate in the event of a dangerous shock to the lamp casing,thereby short-circuiting the current supply if such shock occurs whenthe lamp is alight, and a fuse adapted to melt in the event of thecurrent supply being short-circuited and thereby to disconnect the lampbulbs permanently from the current supply.

6. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, current supply conductors entering the lamp casing and adaptedto be connected outside the lamp casing to an accumulator, a conductinglamp holder plate movably mounted in the casing and conductivelyconnected with one of the supply conductors, a stop against which thelamp holder plate normally bears, a spring tending to hold the lampholder plate against the stop, lamp holders mounted in the lamp holderplate, a plurality of electric lamp bulbs mounted in the lamp holders,each lamp bulb being electrically connected by one terminal with thelamp holder plate, a switch spindle journaled in the casing, means suchas a handle for rotating the switch spindle from outside the casing,means provided on the switch spindle for establishing and interruptingelectric circuits through the several lamp bulbs and the current supplyconductors, a contact spring electrically connected with the othersupply conductor and with the other terminal of the lamps when the lampsare switched on, a contact finger on the lamp holder plate normallylocated in the neighbourhood of the said contact spring and adapted tomove into contact therewith in the event of a dangerous shock to thelamp casing, thereby short-circuiting the current supply if such shockoccurs when the lamp is alight, and a fuse adapted to melt in the eventof the current supply being short-circuited and thereby to disconnectthe lamp bulbs permanently from the current supply.

7. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, an electric lamp bulb mounted in the casing, current supplyconductors entering the lamp casing and adapted to be connected outsidethe lamp casing to an accumulator, a switch spindle journaled in thecasing, means such as a handle for rotating the switch spindle fromoutside the casing, means provided on the switch spindle forestablishing and interrupting an electric circuit through the lamp bulband the current supply conductors, and two plug sockets in the lampcasing, each connected with one of the current supply conductors, andadapted to be plugged into a current supply for the purpose of chargingthe accumulator through the lamp casing.

8. An electric lamp as claimed in claim 7, further comprising a closuremember adapted to prevent access to the plug sockets, and means such asa lead seal for preventing unauthorized removal of the closure member.

9. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, an electric lamp bulb mounted in the casing, current supplyc0nductors entering the lamp casing and adapted to be connected outsidethe lamp casing to an accumulator, a switch spindle journaled in thecasing, means such as a handle for rotating the switch spindle fromoutside the casing, means provided on the switch spindle forestablishing and interrupting an electric circuit through the lamp bulband the current supply conductors, a glass plate closing the lamp casingin the front, a screwthreaded frame ring securing the glass plate inposition, a locking member adapted to prevent the frame ring from beingunscrewed, and means such as a lead seal for preventing unauthorizedremoval of the locking member.

10. An electric lamp as claimed in claim 7, further comprising a glassplate closing the lamp casing in the front, a screw-tl'lreaded framering securing the glass plate in position, a closure member adapted toprevent access to the plug sockets and to prevent the frame ring frombeing unscrewed, and means such as a lead seal for preventingunauthorised removal of the closure member.

11. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, an electric lamp bulb mounted in the casing, current supplyconductors entering the lamp casing and adapted to be connected outsidethe lamp casing to an accumulator, means for establishing andinterrupting an electric circuit through the lamp bulb and the currentsupply conductors, two plug sockets in the lamp casing, each connectedwith one of the current supply conductors, and adapted to be pluggedinto a current supply for the purpose of charging the accumulatorthrough the lamp casing, a glass plate closing the lamp casing in thefront, a screw-threaded frame ring securing the glass plate in position,a closure flap pivoted to the lamp casing and adapted when closed toprevent access to the plug sockets and to prevent the frame ring frombeing unscrewed, and means such as a lead seal for preventingunauthorized opening of the closure flap.

12. An electric lamp adapted to be energized by an accumulator and to beused as a miners head lamp or for like purposes, comprising a lampcasing, current supply conductors entering the lamp casing and adaptedto be connected outside the lamp casing to an accumulator, a conductinglamp holder plate movably mounted in the casing and conductivelyconnected with one of the supply conductors, a stop against which thelamp holder plate normally bears, a spring tending to hold the lampholder plate against the stop, lamp holders mounted in the lamp holderplate, a plurality of electric lamp bulbs mounted in the lamp holders,each lamp bulb being electrically connected by one terminal with thelamp holder plate, a non-conducting switch spindle journaled in thecasing, means such as a handle for rotating the switch spindle fromoutside the casing, contact springs mounted in the casing, conductingprojections on the switch spindle adapted to place the contact springsin electrical connection with one another in pairs in certain positionsof the switch spindle, thereby establishing electric circuits throughthe lamp filaments and the current supply conductors, a contact springelectrically connected with the other supply conductor and with theother terminal of the lamps when the lamps are switched on, a contactfinger on the lamp holder plate normally located in the neighborhood ofthe said contact spring and adapted to move into contact therewith inthe event of a dangerous shock to the lamp casing, therebyshort-circuiting the current supply if such shock occurs when the lampis alight, a fuse adapted to melt in the event of the current supplybeing short-circuited and thereby to disconnect the lamp bulbspermanently from the current supply, two plug sockets in the lampcasing, each connected with one of the current supply conductors, andadapted to be plugged into a current supply for the purpose of chargingthe accumulator through the lamp casing, a glass plate closing the lampcasing in the front, a screw-threaded frame ring securing the glassplate in position, a closure flap pivoted to the lamp casing and adaptedwhen closed to prevent access to the plug sockets and to prevent theframe ring from being unscrewed, and means such as a lead seal forpreventing unauthorized opening of the closure flap.

In testimony whereof I have signed my name to this specification.

PAUL WOLF.

